The present invention generally relates to rotary recording medium reproducing apparatuses capable of placing and leaving a rotary recording medium in a state possible for reproduction within the reproducing apparatus when a jacket having a lid for accommodating the recording medium therein is inserted into and then extracted from within the reproducing apparatus, and also capable of incasing the recording medium within the jacket so that the recording medium can be obtained outside the reproducing apparatus together with the jacket, when the empty jacket is inserted into and then extracted from within the reproducing apparatus. More particularly, the present invention relates to the above type of a rotary recording medium reproducing apparatus having a jacket opening enlarging mechanism for enlarging an opening of the jacket which is inserted into the reproducing apparatus upon loading and unloading of the recording medium with respect to the reproducing apparatus, wherein the jacket opening enlarging mechanism is provided with a locking mechanism which is maintained in a locked state even upon insertion of the case or the jacket if the insertion is not normal and is released of the locked state only when the case or the jacket is inserted in a normal position.
Conventionally, in an apparatus for reproducing a rotary recording medium (referring to a video disc, PCM audio disc, and the like, and hereinafter simply referred to as a disc), there are types of apparatuses in which the disc is reproduced when the disc is loaded upon clamping and placing of the disc within the reproducing apparatus, by inserting into and then extracting a jacket (disc case) which has a lid and accommodates a disc therein, from within the reproducing apparatus. As a conventional apparatus of this type, a reproducing apparatus was proposed in a U.S. patent application Ser. No. 231,868 filed Feb. 5, 1981, entitled DISC-SHAPED RECORDING MEDIUM REPRODUCING APPARATUS, now U.S. Pat. No. 4,352,174, in which the assignee is the same as that of the present application. This previously proposed reproducing apparatus operates together with a disc case comprising a jacket which has a space for accommodating a disc and an opening for allowing the disc to go in and out of the jacket, and a lid member inserted through the jacket opening for closing the jacket opening, where the reproducing apparatus comprises an inserting opening through which the case is inserted, a turntable for rotating the disc, holding means for holding at least one of the disc and the lid member provided at an innermost part on the opposite side from the inserting opening with respect to the turntable, a jacket opening enlarging mechanism provided in the vicinity of the inserting opening, capable of moving over the turntable between the position in the vicinity of the inserting opening and the innermost part of the reproducing apparatus, for enlarging the jacket opening by entering inside cutouts of the lid member upon insertion of the jacket into the reproducing apparatus through the inserting opening, lowering and raising means for lowering the disc to a position where the disc is placed on the turntable from a holding position where the disc is held by the holding means upon starting of the reproduction, and raising the disc to the holding position from the turntable upon finishing or discontinuing of the reproduction, a reproducing transducer for reproducing the disc placed onto the turntable, and moving means for moving the reproducing transducer from a waiting position to a reproducing position with respect to the disc.
In the above previously proposed reproducing apparatus, a locking mechanism is provided for locking the jacket opening enlarging mechanism in the vicinity of the inserting opening. This locking mechanism is provided in order to prevent the enlarging mechanism from moving, when the reproducing apparatus receives a shock upon transport or the operator pushes the enlarging mechanism by his finger tips in mischief, for example. The locking mechanism is independently provided on both the right and left end sides of the enlarging mechanism. These locking mechanisms are simultaneously released by being pushed by the case, when the case is inserted through the inserting opening, to allow the enlarging mechanisms to move according to the insertion of the case.
On the other hand, if the manner in which the case is inserted into the reproducing apparatus, it is normal for the case to be inserted straight in a position where the front surface edge thereof is parallel with the enlarging mechanisms. However, in some instances, the case may be inserted into the reproducing apparatus in a special manner, in which the rear edge of the case along the inserting direction which is held by the operator is repeatedly swung to the right and left. During such a special case inserting operation, the right and left locking mechanisms are released alternately, and one of the locking mechanisms constantly remain in the locking state. Hence, the enlarging mechanism is maintained in the locked state and usually does not move, although the locking provided by the locking mechanisms is incomplete. However, if the case is swung swiftly, for example, the following movement of the locking mechanisms towards the returning direction is delayed, and the right and left locking mechanisms both assume the lock releasing state. As a result, the locking with respect to the enlarging mechanism is released, and the enlarging mechanism is pushed by the case and is caused to move towards the innermost part of the reproducing apparatus. On the other hand, as will be described hereinafter, the positional relationship between the case and the enlarging mechanism in the above state becomes such that the front edge of the case is inclined with respect to the enlarging mechanism. That is, the enlarging mechanism may assume a state where one or both pairs of enlarging fingers of the enlarging mechanism do not engage with the opening of the inserted jacket, for example, that is, the enlarging mechanism may assume a state deviated from the normal state. Under such circumstances, even when the enlarging mechanism operates, the enlarged state of the jacket opening may become incomplete, or the jacket opening may not be enlarged at all. If the case or the jacket is inserted in a state where the enlarged state of its opening is incomplete, the loading of the disc into the reproducing apparatus and the recovery of the disc within the jacket cannot be carried out in a normal manner, and abnormal loading and recovery of the disc takes place. Moreover, an accident may occur in which the recording surface of the disc is scratched by the jacket when the disc enters and leaves the jacket.